Fishes

To evaluate the potential of compound attractants in ameliorating diet-induced intestinal dysfunction in Siniperca chuatsi fed commercial compound feed, this study investigated their effects on intestinal metabolism and microbiota composition. In this study, four distinct diets are formulated: a control diet without attractants and three experimental diets supplemented with compound attractants A (nucleotides and L-glutamic acid), B (nucleotides, L-glutamic acid, and allicin), and C (nucleotides, L-glutamic acid, and betaine). Over a period of 8 weeks, groups of S. chuatsi were fed these diets, after which we assessed the intestinal microbiota and transcriptomic responses. KEGG pathway analysis of differentially expressed genes (DEGs) indicated that the A group exhibited significant changes predominantly in intestinal cholesterol homeostasis and inflammatory responses. The B group showed DEGs primarily associated with mucosal immune functions and pro-inflammatory cytokine signaling. Diversely, the C group revealed DEGs chiefly tied to immune and inflammatory response pathways. Furthermore, the intestinal microbiota exhibited beneficial modifications at both the phylum and genus levels in the A and B groups, while such beneficial shifts were not observed in the C group. These findings indicated that dietary supplementation with compound attractants A and B could positively influence both the intestinal transcriptomic landscape and microbiota composition in S. chuatsi, highlighting their potential as effective additives in compound feeds for aquaculture.

To assess the status of Coilia nasus resources in the Yangtze River Estuary and support evaluation of fishing ban effectiveness, this study integrated fishery resource survey data and environmental variables collected from 2023 to 2025. A generalized additive model (GAM) was applied to examine post-ban recovery patterns of C. nasus and the environmental drivers shaping its spatiotemporal distribution. The results revealed pronounced seasonal variation in biomass, with autumn (November) values significantly higher than those in spring and summer. Biomass peaked in autumn 2024, forming a persistent and highly concentrated aggregation. Spatial analyses further indicated that high-biomass areas were consistently distributed within the brackish-water mixing zone of the outer estuary, corresponding to migratory pathways and foraging requirements of the species. GAM results demonstrated that the spatiotemporal distribution of C. nasus was jointly regulated by multiple environmental factors. In spring, temperature, depth, transparency, pH, dissolved oxygen (DO), and chlorophyll-a (Chl-a) exerted significant effects; in summer, salinity and pH were the dominant drivers; and in autumn, temperature, pH, salinity, DO, ammonium (NH₄⁺–N), nitrate (NO₃⁻–N), and phosphate (PO₄³⁻–P) showed significant influences. This study provides scientific evidence to support the management of C. nasus resources, particularly in the brackish-water mixing zone of the outer Yangtze River Estuary, and to improve evaluation of fishing-ban effectiveness.

Integrated multitrophic aquaculture (IMTA) emerges as a sustainable strategy to control the excess of solids and inorganic nutrients that tend to increase in the biofloc system (BFT) cycle, since the model integrates organisms from different trophic levels sharing the same system and nutrients. Thus, this study compared a Penaeus vannamei monoculture system with an integrated biofloc system including Mugil liza, Holothuria grisea, Crassostrea tulipa, and Salicornia neei, focusing on water quality and the performance of organisms and systems. This study consisted of three monoculture systems (16 m³; 375 shrimp m⁻³) and three IMTA systems, composed of a shrimp tank (16 m³), a mullet tank (4 m³; 30 ind m⁻³), a combined tank (3 m³) for oysters (45 ind m⁻³) and sea cucumbers (3 ind m⁻²), and a Salicornia neei bed (2.78 m²; 37 ind m⁻²). All IMTA systems operated in recirculation without water exchange, using 10% of the established biofloc inoculum. The IMTA system had half the hydrated lime use (2.13 vs. 4.29 kg), lower solids (299.56 vs. 373.33 mg L⁻¹), and reduced sludge production (9.37 vs. 15.87 kg). Shrimp growth was similar in both systems. Mullet grew adequately with a survival rate of 95.8%, but oysters showed a survival rate of 45.7%. Sea cucumber had a survival rate of 100% until day 28, when a marked decline appeared, strongly correlated with rising temperature (>28 °C; r = −0.71). This resulted in a significant increase in solids in the last weeks, suggesting that the population decline reduces solids control capacity. Furthermore, the biofloc in IMTA was dominated by coccoid forms, with lower proportions of filamentous and cyanobacterial forms.